Error Code

Error Description

Possible Cause

What to Do

E0

Hot water sensor failure

Junction port loose, short circuit

Call for service

E1

Ignition system failure

The gas valve is not opened or fully opened. Water shut-off valve is not open, Junction port loose.

Check and open gas fully, Check and open water valve, Call for service.

E2

There is flame when no water is coming in

Electric circuit problem

Call for service

E3

Over-heating protection

Dry combustion, problem of overheating controller

Call for service

E5

Pressure switch

Motor problem. Voltage of power supply is too low

Call for service

E6

Over-heating

Gas pressure is too high, water shutoff valve is not fully opened. The temperature is set too low.

Check shut-off valve and open fully. Increase temperature setting.

E7

Solenoid Valve

Open Circuit of the valve, short circuit of the valve, none of the above

Connect the valve, replace the valve, replace the computer board.